Wayne, sorry i took so long to jump in on this one. I love keris with the kul buntet pamor. I own 2 myself. Something very mystical and archetypical about that swirling spiral.
I boast no real skills at judging tangguh, but i will go out on a limb and suggest that this keris is genuinely old. How old i can't say but i would imagine at least 16thC. As for the keris bag, these are very traditional and i have one for most of my keris. None of mine have any embroidery on them, but they come in all different types of material. Does anyone know the traditional name for these?
Pusaka means heirloom and refers to any sacred object of power that is passed down through the generations. This is about the transference of power and i believe this idea originally started on the royal level with the practice filtering down to the common man. It is an arguable point, but my feeling tends to be that once the chain is broken the keris cannot rightfully be called pusaka.